The present invention generally relates to excavating apparatus and, in a preferred embodiment thereof, more particularly provides a uniquely configured excavating tooth point and adapter assembly representatively including a tooth point connected to an adapter section having interconnected main and intermediate portions.
Large excavating buckets, dippers and the like are typically provided with a series of earth-cutting tooth assemblies each comprising a relatively large adapter section and a relatively small replaceable tooth point. The adapter section has a base portion which is connectable to the forward lower lip of the bucket, and a tapered nose portion onto which the tooth point is removably secured, with the tapered adapter nose being received in an interior pocket portion of the point, by a suitable connecting pin or other connecting structure. Compared to that of the adapter section, the useful life of the point is rather short, the adapter section typically lasting through several point replacements until the tremendous earth forces and abrasion to which the adapter section is subjected necessitates its replacement. Thus, the point may be characterized as a wear member, and the adapter section may be characterized as a support structure carrying the wear member and protected thereby against premature replacement.
The adapter section may be a single adapter, or may be formed from a primary adapter which is connectable to the bucket lip, and an intermediate adapter which is interposed between the replaceable tooth point and the primary adapter and releasably connected to them. The intermediate adapter has a front nose portion which is captively and releasably retained within a complementarily configured rear end pocket area of the point by a first connector structure, and the main adapter has a front nose portion which is captively and releasably retained within a complementarily configured pocket area in the rear end of the intermediate adapter by a second connector structure. Thus, the replaceable tooth point functions as a wear member carried on and protecting the intermediate adapter, with the intermediate adapter functioning both as a support structure for the point and a wear member for the main adapter which supports the intermediate adapter.
Designing the configuration of an adapter nose, its interfit with its associated wear member (such as a point or another adapter), and its relationship with the connector structure used to releasably couple the adapter nose to the associated wear member, presents a variety of engineering challenges. For example, to maximize the earth penetration capabilities of a particular adapter/tooth point assembly the frontal cross-section of the assembly must be as small as possible. However, in adapter/tooth point assemblies of conventional designs reductions in such frontal cross-sectional area correspondingly weakens the assembly. Other design challenges include preventing undue operational stresses from being imposed on the wear member/support member connector apparatus, configuring the nose to reduce operational stress concentrations thereon, stabilizing each wear member against excess movement relative to its associated support member during excavating operations, and optimizing the abrasion protection provided to each support member by its associated wear member.
It would be desirable for both economic and operational reasons to provide an adapter/tooth point assembly having improvements in one or more of these design areas. It is to this goal that the present invention is primarily directed.
In carrying out principles of the present invention, in accordance with a preferred embodiment thereof, a specially configured excavating equipment wear member/support member assembly is provided which extends lengthwise along a front-to-rear assembly axis and representatively includes a replaceable tooth point, an intermediate adapter, and a main adapter. The tooth point is telescoped onto and captively retained on a forwardly projecting nose portion of the intermediate adapter, and the intermediate adapter is telescoped onto and captively retained on a forwardly projecting nose portion of the main adapter. The main adapter has a rear end portion which is releasably securable to a front edge portion of an excavating bucket lip.
The nose portion of the intermediate adapter projects forwardly from a front end surface of a rear base portion of the adapter, which representatively circumscribes the rear end of the nose portion, and has a horizontally elongated, generally elliptical cross-section along substantially its entire front-to-rear length, top and bottom surfaces, and horizontally opposite left and right surfaces. Horizontally opposite stabilizing projections are disposed on and project laterally outwardly from he left and right surfaces of the nose portion, and a connector opening extends horizontally through the nose portion and opens outwardly through the stabilizing projections. Preferably, the stabilizing projections are stabilizing bosses having rectangular configurations, are positioned adjacent the front end surface of the rear base portion of the intermediate adapter, and extend through only a relatively small portion of the front-to-rear length of the nose portion.
The intermediate adapter nose is complementarily received in a rear end cavity of the tooth point, with horizontally opposite connector openings extending through opposite left and right side walls of the tooth point into interior side recesses therein which complementarily receive the stabilizing bosses on the intermediate adapter nose. The tooth point connector openings are in an outwardly overlying align ed relationship with opposite ends of the intermediate adapter nose connector opening, and a connector structure, representatively a front connector pin, horizontally extends through the point and adapter connector openings and captively retains the tooth point on the intermediate adapter nose.
Preferably, the top and bottom surfaces of the intermediate adapter nose are substantially parallel to the front-to-rear assembly axis, and the top and bottom nose surfaces have front portions which are vertically inset from the balance of the top and bottom nose surfaces.
The main adapter has a rear base portion with a front end surface from which a nose portion forwardly projects, the main adapter nose portion having a configuration similar to that of the intermediate adapter nose, and is similarly provided with outwardly projecting stabilizing bosses on opposite left and right sides thereof, a connector opening extending horizontally through the main adapter nose and opening outwardly through its stabilizing bosses. The main adapter nose and its associated stabilizing bosses are complementarily received within a rear end cavity of the rear base portion of the intermediate adapter. The main adapter nose connector opening is aligned with left and right side wall connector openings formed in the base portion of the intermediate adapter, and a connector structure, representatively in the form of a rear connector pin, extends through the aligned connector openings and captively retains the intermediate adapter on the nose of the main adapter.
Facing front and rear end surfaces of the intermediate adapter base portion and the tooth point have alternately scalloped portions around their peripheries, the scalloped peripheries being complementarily engaged in an interlocking configurational relationship. Preferably, top and bottom portions of the front end surface of the rear base portion of the intermediate adapter have forwardly convex arcuate configurations, and left and right side portions of the front end surface of the rear base portion of the intermediate adapter have rearwardly concave arcuate configurations. In this manner, the front connector pin location may be advantageously positioned further rearwardly on the intermediate adapter.
In a similar manner, facing front and rear end surfaces of the main adapter base portion and the intermediate adapter have alternately scalloped portions around their peripheries, the scalloped peripheries being complementarily engaged in an interlocking configurational relationship. Preferably, top and bottom portions of the front end surface of the rear base portion of the main adapter have rearwardly concave arcuate configurations, and left and right side portions of the front end surface of the rear base portion of the main adapter have forwardly convex arcuate configurations. In this manner, top and bottom side portions of the intermediate adapter extend rearwardly over corresponding underlying portions of the main adapter and provide enhanced wear protection for the main adapter.
Compared to tooth point/adapter assemblies of conventional configurations, the complementary configurations of the adapter noses and their associated point and adapter cavities provide the tooth point/adapter assembly with a variety of advantages including smaller size with similar strength, reduced frontal area which facilitates assembly earth penetration, enhanced rotational stability among the tooth and adapter components, and reduced operational stresses on the connector pins. While the illustrated embodiment of the invention includes a two-piece adapter section, it will be readily appreciated by those of skill in this particular art that the adapter section could alternatively be defined, if desired, by a single adapter member. Additionally, while principles of the present invention have been representatively illustrated herein as being embodies in a tooth point and adapter assembly, it will further be appreciated by those of skill in this particular art that such principles could also be utilized to advantage in other types of excavating equipment wear member/support member assemblies as well.